


In the Name of Pseudoscience

by Junebug1312



Category: CrankGameplays - Fandom, Crankiplier - Fandom, markiplier - Fandom
Genre: Blow Jobs, Dirty Talk, Friends to Lovers, Hand Jobs, Horoscopes, M/M, Neck Kissing, Nipple Play, Smut
Language: English
Status: Completed
Published: 2020-03-21
Updated: 2020-03-21
Packaged: 2021-03-01 04:14:26
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,619
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23239036
Author URL: https://archiveofourown.org/users/Junebug1312/pseuds/Junebug1312
Summary: "You would be willing to have sex with me..." Ethan closed his eyes struggling to find the words, "...in the name of science?""In the name of pseudoscience actually but you're getting the idea" Mark smirked, eyes glinting with determination.
Relationships: Mark Fischbach/Ethan Nestor
Comments: 29
Kudos: 665





	In the Name of Pseudoscience

**Author's Note:**

> I was writing this as the recent video came out and might I say neither the father, the sun or the Holy Spirit could prepare me for the fuckery that was that video lol
> 
> Also Mark, sweetie, you was right. That video was straight up fanfic fuel. So here you go ;)

'It seemed like a good idea at the time' was a common phrase used on the Unus Annus set. From everything to packing a wall full of ramen to getting pepper-sprayed. Mark and Ethan would laugh about this constantly fully knowing that whenever that phrase was muttered whatever they had just done was most certainly not a good idea at the present or future time. This was one video Ethan didn't feel like that needed to be said. No one was getting physically or emotionally harmed, it was all just a bit of fun. And to Ethan and Mark, a whole lot of make-believe bullshit. 

Horoscopes. The language of our universe used to understand our emotions and actions. For Mark and Ethan, it was all just another video concept that would surely make their viewers chuckle. Of course, that was great in theory but their Unus Annus videos always had a way of bringing things up that were better off not mentioned or discussed. During the video Ethan and Mark were cracking jokes about their sexual compatibility, Ethan even went as far as screaming that he and Mark should fuck. And they were laughing hysterically because the idea was ridiculous! No matter how much the fans wanted it, no matter how compatible their signs were Mark and him were never going to fuck.

But after the video...Ethan's mind couldn't help but wander back to their horoscopes. On one hand, it was completely obvious to Ethan that these articles meant nothing but on the other...it made him question some things he had never thought about before.

"That was such a bunch of bullshit" Mark laughed, sitting down on the couch with a glass of water.

"I know right" Ethan agreed though his mind was racing, "But what if there is the slightest chance that there's some truth to it?"

Mark scoffed and took a sip of his water, "You really think that some teenager on the internet can predict two peoples compatibility?"

Ethan rolled his eyes, "No _Mark_ I'm just saying that some of what they were stating was pretty accurate to our personalities"

Mark's eyes grazed over him, making Ethan shrink down into the couch further. If Ethan had less pride he would have let his gaze fall as well.

Mark sighed exasperatedly, "I know that face, Ethan. If you have something you wanna say then say it"

Ethan chewed on his lip, a nervous habit of his, and cast his eyeline up to the ceiling. Was it really worth bringing up to Mark? Or would it just make things awkward?

"Oh my god, Ethan I—"

"Fine!" Ethan exclaimed, "It's just...don't you find it kind of odd that if we weren't friends we could be in like...a super-steamy relationship right now?"

Mark bit his lip clearly trying to hold in a laugh, "Ethan we agreed that it's all bullshit. Our stars aligning means absolutely nothing in relation to how good our sex would be!"

Ethan's cheeks heated up at Mark explicitly stating what was running through his mind. Ethan didn't like that his brain was now supplying him with questions such as 'but what if the sex was good?' because that was all he was going to be able to think about now. No matter how much the internet loved to talk Ethan did not daydream about Mark. Not his hair or his chest _or_ having sex with him. Eventually, Ethan's brain would let this go and move onto the next segment of weirdness in their lives.

"I know! I know...I just can't help but wonder if there is even the tiniest bit of truth to it" Ethan admitted, "But you're right it's not real"

There were a few seconds of questionable silence that left Ethan feeling uneasy. Did he make Mark uncomfortable and that's why he was staring persistently at the ice in his cup of water? Ethan coughed awkwardly and got up from the couch.

"So you wanna go film our next—"

"What if we tried it?" Mark interrupted.

Ethan did a double-take, his eyebrows raising, "Tried what?"

Mark pursed his lips, a key signature that he was about to suggest a really bad yet amusing idea.

"What if we tested our horoscopes accuracy?"

Ethan felt a lump in his throat, he let out a nervous chuckle, "Still not catching on Mark"

Except that was a lie because Ethan was almost positive about what Mark was proposing but he wasn't going to be the first one to say it. Mark placed his glass down cautiously onto the table moving a coaster underneath it as an afterthought. Ethan laughed internally knowing Mark was only doing it so Amy wouldn't yell at him.

"'Steamy passionate sex?'" Mark quoted, "Kind of piqued my interest how about yours?"

"I don't think that was it word for _word_ —"

"Ethan" Mark's stare was unrelenting.

Ethan gulped and didn't even attempt to hold Mark's gaze this time.

" _Fine,_ ok...it got me curious"

"Ok!" Mark exclaimed clapping his hands together, "So what do you say we give it a go?"

Ethan choked on his spit there was no pretending to misinterpret that message.

"You would be willing to have sex with me..." Ethan closed his eyes struggling to find the words, "...in the name of science?"

"In the name of pseudoscience actually but you're getting the idea" Mark smirked, eyes glinting with determination.

Ethan laughed in disbelief, "You know I thought you were insane when you suggested pepper-spraying our own faces for entertainment purposes but this plan has got to take the cake"

Mark walked towards him pointing his finger at him enthusiastically, "But you see that was also in the name of science! And aren't you glad you now know what that feels like?"

Ethan blinked slowly then exclaimed, "No Mark I'm not!"

"Listen just hear me out ok?" Mark explained, "You clearly are as inquisitive as I am about the authenticity of our horoscopes and this is a perfect way to determine that! You're single, I'm single so no harm no foul right?"

" _No harm no_..." Ethan trailed off shaking his head in incredulity, "What about our friendship Mark?"

"It's sex Ethan I'm not asking you to marry me" Mark stated, "If it gets uncomfortable at any point and we aren't feeling it, we'll call it"

Ethan opened his mouth a few more times before realizing all of his arguments were pointless and led to dead ends. And Mark...damn it...was actually making some good points. Or at least points that had _some_ sound logic to them. Sex with Mark. Ethan having sex with Mark. The idea was sounding less and less crazy. Ethan still blamed Mark for using brainwashing techniques to convince him to get pepper-sprayed maybe this was just another example of that. Or maybe Ethan didn't have as much resolve to sleeping with Mark as he hoped he would.

Ethan sighed heavily and crossed his arms, "Ok...how do we get started?"

Mark smirked happily as he always did when he got his way. Still, he looked as irresolute as Ethan felt. It was odd seeing Mark so vulnerable since he always tried to make the impression he was dominant in every area of life. Flashes of the article sped through Ethan's mind, Cancers were complacent in certain situations perhaps sex was one of them?

Ethan closed the distance between them making Mark's eyes widen. He grabbed Mark's shoulders and massaged them gently almost expecting Mark to hit him with a 'don't touch me!' as he would in their videos.

"Relax, it's just me"

Mark breathed out slowly tacking a chuckle onto the end of it. Mark being nervous was so out of character Ethan felt himself slip into a new position to match Mark's role reversal. Suddenly it was all up to him.

"Why don't you try one of your shitty pick up lines on me?" Ethan suggested smiling teasingly.

Mark rolled his eyes, "First of all nothing I do is shitty."

Ethan hummed sarcastically in reply with a condescending head nod. 

" _Secondly_...baby, I wish I was DNA Helicase so I could unzip your jeans" Mark threw a lacklustre wink at the end.

Ethan huffed out a pity laugh, "Oh my god that was the worst—"

Next thing he knew Mark's lips were on his cutting off his words, Ethan's eyes widened until he caught on and let them drift closed. Mark's lips were soft and Ethan's were buzzing as they came in contact with the mint chapstick Mark used earlier. One hand left Mark's shoulder to cup his cheek deepening the kiss. God, it had been too long since Ethan had kissed anyone, the simple affection was nice. Eventually, Mark pulled back and inspected Ethan's face to check his reaction.

"Well..." Ethan's voice was hoarse, he cleared his throat, "That's not the worst place to start"

He pulled Mark back in and continued to make out with him. For how much resistance Ethan had to this plan initially with each trace of Mark's tongue he was losing every complaint or reason to not do this he had to begin with. Ethan would swear on his life he had never pictured Mark this way but the small sighs pushing past Mark's lips were blurring the lines of past and present in Ethan's head. His other hand moved from Mark's shoulder to his hip pulling his body closer to his. A moan vibrated against Ethan's lips as he did this making Ethan whine in response. Mark pulled away albeit reluctantly.

"Ok so I'd say...kissing...is a check..." he said breathlessly.

Ethan swallowed and nodded his head letting his forehead rest against Mark's for a moment, "I'd...I'd say so"

"Clothes off?" Mark inquired.

A wave of anxiety crashed down on Ethan but he pushed the fear into the deepest pits of his stomach. He was light-headed from kissing Mark and accepting Mark's suggestions sounded so much easier than opposing. This did not make it any easier to actually remove his clothing though. Mark had seen Ethan shirtless enough, hell he had seen him in skin-tight nude underwear but never had he asked Ethan that same question with that glimmer of desire in his eyes. Tentatively both boys threw off their shirts and Ethan had never derived so much pleasure from Mark's chest before then at this moment. Sure he knew he was fit, Mark wouldn't stop throwing that in Ethan's face but this time Ethan was able to just appreciate how toned Mark was instead of comparing himself. And it was obvious Mark was feeling the same way as his eyes slithered down Ethan's chest.

Ethan got a head start on his pants but Mark was quick to follow. Now that they were both in their underwear the reality of their situation struck Ethan.

"Fuck we...we're really doing this aren't we?"

Mark nodded slowly, his gaze snapping from Ethan's bare legs to his eyes, "You good?"

Ethan exhaled steadily, "Yeah, yeah I'm good"

He placed a hand on Mark's chest and applied a little force, enough to push Mark backwards onto the couch. Mark's eyes widened as a tiny smirk danced on his lips.

"Gonna finesse me with your sexual prowess now?" Mark asked, biting his lip.

"Gotta get accurate test results right?" Ethan responded grinning.

Ethan gulped but went ahead with his plan of action. Kissing was one thing, a spin the bottle setup could have prompted that. But the route they were headed down was premeditated. He placed both legs on either side of Mark sufficiently straddling him now and he repressed a chuckle as it reminded him of the Kings Royal Fitness Test video they did with Alex. His hands drifted to Mark's shoulders again as Mark hesitantly placed his hands on Ethan's waist. Still not fully seated Ethan looked down at Mark with doubt circling his pupils.

"This ok?"

Mark's eyes were glossed over with anxiety and want as he stared up at Ethan. Without saying anything he dug his fingers into Ethan's skin gently and pulled him down so his ass was directly positioned on his crotch. A choked breath got stuck in Ethan's throat as he felt Mark's half-hard dick pushing into his butt.

"I've gotta say Ethan so far I'm not that impressed" Mark taunted, "I thought Scorpio's were pure raw sexual energy"

Ethan rolled his eyes but played along with Mark's game, "And I thought Cancer's were supposed to be romantic?"

"Didn't think you were the roses and dinner type" Mark joked.

Ethan scoffed with a faux offence, "Are you calling me easy?"

"Maybe" Mark provoked, "You gonna prove me wrong?"

Ethan grinned toothily, he snuck his lips up to Mark's ear, "You're playing a dangerous game Fischbach"

Without prompting Ethan cheekily bit Mark's earlobe eliciting a shaky moan from Mark. He shifted lower and kissed Mark's neck lightly before grazing his teeth over the sensitive skin. A plethora of curse words was running through Ethan's head as he licked and sucked gently at the skin not wanting to provide any more editing work to cover up hickeys. His brain kept reminding him that this was _Mark_. He wished it would just shut up.

Soon enough Mark was shivering under Ethan's touch, letting out a particularly whiny moan when Ethan sucked on his pulse point. His hips bucked up into Ethan making him freeze for a moment. Mark's very hard dick was now pressing up against Ethan's ass, not that Ethan could blame him when his own very hard dick was poking into Mark's stomach. Mark was tense underneath him and Ethan could only assume the same thoughts were flitting through his head. Maybe this had gone too far? They were friends. But Mark wasn't going to call it off, Ethan already knew that so either it was up to him to stop this or...

His hips swivelled applying pressure downwards, rolling over Mark's crotch perfectly forcing a groan out of Mark's throat.

"Seems like someone is easy" Ethan teased, "But it's not me"

Mark chuckled throatily and dug his fingers harder into Ethan's side making him flinch from the sudden pressure, "Well as we found out apparently I'm rather _easy_ to arouse" 

Ethan rolled his eyes and nipped playfully at the base of Mark's throat. Ethan continued to push his body down, letting Mark rut up into him cut off moans pushing past his lips. The air around them was hot and fervent and every time Ethan rotated his hips, his hard-on rubbed against Mark's hard stomach. Both boys were dwindling into flustered, horny messes only capable of moaning and grinding. Ethan pulled back and watched Mark's face for a few moments, scrunched up in pleasure, his teeth digging into his bottom lip. It was so absurdly hot that it blurred Ethan's senses for a second and as per usual his brain started to supply him with unwarranted thoughts. 

" _Fuck_ " Ethan muttered his eyes glued to the rising blush on Mark's face.

Now that fuck meant a few different things. Fuck this was a bad idea, fuck he never should have brought up the video in the first place and fuck...Ethan was into this. He was into Mark. And he had just never taken the time to fully realize it. And the last _fuck_ was because for sure one of them was going to get hurt now and Ethan had a sneaking suspicion it was going to be him.

He slid off of Mark's lap somehow gracefully even in his turmoil. Mark's half-lidded eyes popped all the way open as he watched Ethan fall to the floor onto his knees. Mark's eyes enlarged catching on quickly to where Ethan's head was at.

" _Fuck_ Ethan...you sure?"

Ethan swallowed slowly, no he wasn't fucking sure. But if Ethan was only going to get to sleep with Mark once for an "experiment" he was going to take advantage of it.

"I'm sure" Ethan confirmed, slight attitude in his tone "All in the name of pseudoscience right?"

A twinge of hurt passed briefly on Mark's face so fast that Ethan couldn't tell if it had actually happened or not. He ignored it, for now, the sound of blood pumping in his ears distracting him from Mark's feelings. Ethan moved his lithe fingers to the waistband of Mark's boxers and silently asked for permission with his eyes. Mark clenched his fists as he exhaled a long diminishing sigh when he relaxed his hands a quick nod was all Ethan received. Running with it Ethan tenderly slipped his thumbs into the waistband and began to pull as Mark lifted his ass so Ethan could remove the fabric. As it was shed Ethan felt the nerves pierce his skin again, he was about to see Mark naked. And hard. 

Once the offending piece of clothing was hanging loosely by Mark's feet Ethan allowed himself to look even though he was still in the platonic headspace of respecting Mark's privacy. Ethan's mouth watered at the sight, his dick was proportionate, long and thick with a purple hue at the tip. Of course, Mark had to be hot and have a huge dick. The world just wasn't fair sometimes.

"Fuck you" Ethan mumbled in disbelief.

Mark's eyebrows flew upwards as amusement shimmered in his dark chocolate eyes, "What did I do?"

Ethan motioned towards Mark's dick, "This is just unfair"

Mark chuckled, "What? You have a problem with my _HUGGGGEEE_ dick?"

Ethan smiled dryly, "Nah, just your _HUUUGE_ head"

Mark pouted jokingly forcing a giggle out of Ethan's lips even as he tried to remain deadpan. He brought a hand up to close around Mark's dick trying to not think too hard about it. As soon as his fingers came in contact with it Mark whimpered lightly, desperation etched on his face. Ethan didn't hold out on him any longer he stroked a few times, slow and tight-gripped, he could tell by the way Mark was biting his lip again that he liked it. Then Ethan moved onto phase two, bringing his head in closer. Mark couldn't keep his eyes off of him as Ethan kissed gently on Mark's thighs sucking deeper where the marks could be hidden. Mark's groans were rough and scratchy and Ethan couldn't wait any longer.

In an attempt to not think too hard on what he was about to do Ethan engulfed Mark quickly. Mark sucked in a sharp inhale and instantly moved his hands from the couch to Ethan's hair. Ethan's breathing picked up as he circled his tongue around the tip, dipping into the slit and relished in the whiny growls falling from Mark's mouth. Ethan's fingers gripped Mark's thighs to keep him stable causing Mark to whimper at the mix of pain and pleasure enrapturing him. 

"Fuck" Mark gnarred.

Ethan removed his mouth and began kissing up and down Mark's length licking along the veins. Ethan was in no way some sort of sexual deviant but with the dumbfounded, wonderous look Mark was sending his way he felt some underhanded judgement. He wrapped his pretty pink lips around Mark again sucking experimentally at the tip gauging Mark's reactions. Mark trembled and was noticeably trying to keep his hips down. Ethan continued to suck faster, drawing more noises from Mark who was pulling just on the side of rough on Ethan's hair. The slight pain didn't deter Ethan if anything it spurred him on. Maybe Mark wasn't the only one with a masochistic side. 

"So— _fuck_ —so _good_ " Mark moaned loudly, head tipped back against the couch.

Ethan was quickly becoming intoxicated with the low timbre of Mark's voice whether he was speaking or moaning. Ethan hollowed his cheeks and sunk further, his throat constricting around Mark which was close to triggering Ethan's gag reflex. 

" _Ethan_ "

Ethan's cock twitched in his boxers. He hadn't expected Mark to say his name during this but suddenly that was Ethan's only goal. Knowing Mark was close Ethan pushed even further truly testing his limits and gripped Mark's thighs harder, swirling his tongue around his length. Flurries of moans soared from Mark's mouth as spots of wetness formed in the corners of Ethan's eyes.

" _Fuck me!_ Ethan...I'm gonna....you're gonna make me..." Mark trailed off breathlessly eyes clenched shut.

Ethan swallowed around Mark's dick, his jaw was hurting like a motherfucker but dammit if he wasn't going to give Mark the orgasm he deserved. His head was spinning as Mark's body tensed and the room went silent, no more noises sputtered into the air. The veins in Mark's arm were popping out as he wrapped his fingers tightly in Ethan's hair, his throat tensed as he was clearly holding his breath. Ethan had half the mind to stop and ask if Mark was alright but only moments later spurts of cum were filling Ethan's mouth making him cough as Mark finally rutted his hips up. Small breathy whines infiltrated the space again as Ethan struggled to swallow all of his cum in one go. Mark's fingers loosening from Ethan's hair signalled Ethan to remove his lips from Mark. And fuck Mark was a mess.

Lips bitten raw, red flushed cheeks and his eyes were lustrous, shining with arousal. Ethan felt a punch of lust to the stomach from the sight as he remembered that he was still hard in his boxers. Mark's chest was heaving with each long-winded breath he took as he let his fingers fall from Ethan's hair down to his chin stroking gently. The touch was surprisingly intimate. 

"Get up here" Mark demanded, his tone controlling Ethan to move instantly.

Mark pulled him in, one hand on his waist and the other on the back of his neck making Ethan fall back into his previous straddling position. As soon as Ethan had reached him Mark's red lips were back on his. Ethan gasped in surprise as Mark traced his tongue over Ethan's lips leaving sparks of pleasure every place it touched. Ethan grabbed onto the back of Mark's head carding his fingers through the dark curls. Mark's tongue darted into Ethan's mouth and brushed alongside his gently. Ethan wondered if Mark liked the taste of himself on Ethan's tongue. A small hum of pleasure left Ethan's lips at the thought causing Mark to shiver. Mark removed his lips and placed gentle kisses from Ethan's chin to his neck. Ethan moaned softly at the feeling of Mark's supple lips tickling his sensitive skin. 

"It's your turn now" Mark whispered against Ethan's skin.

Ethan trembled with anticipation his nails raking down Mark's muscular arms. Mark kissed downwards and continued until he was at Ethan's pecs, he licked a circle around his left nipple. Ethan's head fell backwards at the hypersensitive sensations lighting up his nerve endings. Finally, Mark brushed his tongue teasingly down until it flicked over Ethan's nipple. A whine was pulled from his throat as he rocked his hips forward, his dick needing friction after being neglected for so long. Mark didn't listen though he continued to bite and nip at Ethan's nipple, alternating between the left and the right until Ethan was sweating with need.

"Mark please" he begged.

Mark didn't stop his mouth's movements but one of his hands dropped from Ethan's waist to the front of his boxers. Ethan sighed desperately and scrabbled to push his boxers down enough for Mark to reach his hand inside. The position was awkward but by this point, a light breeze could get Ethan off so it didn't matter much to him. Mark took no time in grasping Ethan, using the copious amounts of precum expelled from his dick to move his hand in long fast strokes. High pitched whines flew from Ethan as Mark continued to nibble on his nipple, blowing cold air every so often to make Ethan tremble. Mark's expert hand stroked skillfully as his fingers toyed with Ethan's slit after noticing how Ethan would whimper every time it was touched. The edge was nearing closer and closer and Ethan didn't think there was anything else Mark needed to do to get him there.

"God you look so _fucking_ hot right now," Mark said breathlessly.

Dirty talk. That bastard. 

"What are you thinking about Ethan?" Mark said lowly, "How _good_ my hand feels? How close you are?"

A strangled whimper escaped Ethan's throat as he began to push his hips into Mark's hand, only seconds away from coming. 

" _Faster_ p-please" Ethan whined, biting the insides of his cheeks to keep himself from begging further.

Mark's speed increased as he stared at Ethan's face twisted in pleasure, "Yeah keep fucking my fist, so hot...you have no idea, Ethan"

Ethan moaned squeakily and came all over Mark's hand pleasure overtaking him. High pitched squeaks settled into low grunts as Ethan's hips eventually came to a stop. Ethan leaned forwards placing both hands on the couch beside Mark's head to stabilize himself.

"So..." Mark trailed off, biting his lip as he was prone to do.

"So..." Ethan answered, "The horoscopes weren't bullshit then"

The room was dropped into thick molasses tension, quiet enough to hear both Mark and Ethan's combined breathing. Mark abruptly cleared his throat, his hand still on Ethan's waist.

"Or..."

Ethan raised an eyebrow and finally leant back so he could see the flush rising on Mark's face. He looked slightly hesitant but if Ethan knew anything about Mark it was that his determination could push him through anything. And he wanted so badly to believe Mark was on the same page as him.

"Or what?" Ethan urged.

"Or the horoscopes _are_ bullshit and our sexual chemistry has nothing to do with that"

"What does it have to do with than Mark?" 

Ethan was testing him, sure. But he could tell the words were on the tip of Mark's tongue and if he said it then Ethan wouldn't feel so alone in his feelings. Mark stared up at him worriedly, his eyes filled with unresolved stress.

"Attraction"

And there it was.

So Mark had come to the same conclusion as Ethan as they were having some of the best sex of their lives. Being a Scorpio or Cancer had nothing to do with the fact that attraction had been an element of their friendship that they never took the time to evaluate.

"You saying you're attracted to me, Fischbach?" Ethan smiled happily, "That's _pretty_ gay ya'know?"

Mark huffed out a crazed laugh, delightfully insane with the recognition that he hadn't just ruined their friendship.

"What a Scorpio thing to say" Mark teased back, smiling fondly up at him.

Ethan let out a deep breath of relief. They were going to be fine.

"I can't believe you somehow convinced me to have sex with you" Ethan chuckled.

"Seemed like a good idea at the time" Mark shrugged, "And turned out to not only be a good idea but a _great_ idea"

Ethan rolled his eyes imitating annoyance but he couldn't cast away the hope present in his expression, "That was lamer than your pick up line"

Mark scoffed, "As if you could do any better" 

Ethan giggled and trailed a hand down Mark's cheek unable to contain the smirk on his face, "The only stars I see aligning are the ones in your eyes babyyy!"

Mark pushed his arm away lightly a grin spreading on his face, "Fuck off Nestor"

Astrology might be real. It might also be bullshit. But the conclusive evidence Ethan could take away from this experiment was that Mark and Ethan were destined to be two stars, side by side, in their own little galaxy. 


End file.
